Left atrial appendage closure and delivery system thereof

ABSTRACT

A left atrial appendage (LAA) closure (1) and a system (6) for delivering the LAA closure are disclosed. The LAA closure (1) includes supporting struts (11), wherein the supporting struts (11) are distributed peripherally around a first hub (10) and extend outward, the supporting strut (11) bifurcates at a first position (110) into a left branch (111) and a right branch (112). The left branch (111) of each supporting strut (11) and the right branch (112) of an adjacent supporting strut join each other at a second position (113) and extend distally to form a distal end. The LAA closure further includes a supporting rod (12) between adjacent supporting struts (11) which ensures stability, absence of irregular deformation and lateral slippage, of the LAA closure (1). With the supporting rods (12) between the adjacent supporting struts (11), the LAA closure (1) forms a dense mesh which imparts high overall strength of the LAA closure (1).

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.16/082,821, filed Sep. 6, 2018, which claims priority of co-pendingInternational Application No. PCT/CN2017/076909 filed Mar. 16, 2017, forwhich priority is claimed under 35 U.S.C. § 120; which claims priorityto Chinese patent application number 201610157997.0, filed on Mar. 18,2016 under 35 U.S.C. § 119; and Chinese patent application number201610379161.5, filed on May 31, 2016 under 35 U.S.C. § 119; the entirecontents of all of which are incorporated by reference.

TECHNICAL FIELD

The present invention relates to the field of medical devices and, inparticular, to a left atrial appendage (LAA) closure and a system forthe delivery thereof.

BACKGROUND

Atrial fibrillation (AF) is the most common arrhythmia seen in clinicalpractice and has an estimated prevalence of 0.5-1.3% in the generalpopulation. Its most significant hazard is that it promotes theformation of blood clots which, when dislodged, tend to be associatedwith complications that may cause a significant increase in morbidityand mortality, such as stroke and occlusion of peripheral vessels.Stroke is the most common and harmful complication of AF, and there areabout 15 million cases of stroke reported globally every year, in which20% to 25% are attributed to AF. Studies show that 60% of rheumatic AFpatients have their cardiogenic clots come from the left atrialappendage (LAA), and over 90% of non-valvular A patients have theirclots formed in the LAA. Therefore, preventing thromboembolism, inparticular stroke, in patients with AF by LAA intervention istheoretically well-founded and of clinical significance.

Anticoagulation is currently employed as a default approach for loweringthe risk of stroke in AF patients, which, however, suffers from a numberof limitations. It is thus of great significance to adopt more effectiveand safer approaches, such as the recently popular LAA closure that isachieved by medical intervention. Commonly used LAA closures aredesigned either as an insert plug, such as the Watchman device, or as adisc-like plug, such as the Amplatzer Cardiac Plug (ACP).

1. Deficiencies and Disadvantages of the Insert Plug Design

A closure of the insert plug design consists of a self-expanding nickeltitanium (nitinol) frame, fixation barbs around the perimeter and apolytetrafluoroethylene (PTEF) porous membrane that separates the atriumbut allows the entry and exit of blood to and from the LAA.

When inserted into the LAA, a closure of this design cannot completelyseal off the LAA orifice due to an irregular shape of the LAA orificeand limited deformability of the closure itself, still leaving a channelfor the formation of a clot in the LAA due to AF. In addition, the LAAis a multi-lobed structure varying in shape and depth among individuals,and the closure cannot adapt to all possible LAA anatomies. Further, itsuffers from insufficient anchoring.

2. Deficiencies and Disadvantages of the Disk-Like Plug Design

A closure of the disc-like plug design is a double-disk closureconsisting of a lobe that anchors inside the LAA and a disk, the lobeand the disk being connected by a thinner waist. The lobe inside the LAAis configured to avoid dislocation of the device, and the disk isconfigured to seal off the LAA orifice.

The lobe and the disk of this closure are integral with each other andneither of them can deform completely independently of the other. As aresult, after the lobe is positioned inside the LAA and the disk isbuckled at the LAA orifice, the disk may not satisfactorily seal the LAAorifice under traction from the lobe and may fail to achieve a desiredocclusion effect. Moreover, the lobe and the disk are both limited inlengthwise adjustability, and hence difficult to achieve a favorableanchoring and blood flow blockage effect. Again, the disk of this designis also incapable of adapting to various possible LAA anatomies.

Furthermore, the insert plug design and the disc-like plug design bothsuffer from insufficient strength.

In this regard, there is an urgent need in the art for a solutioncapable of better loading or deployment of an LAA closure.

SUMMARY OF THE INVENTION

An objective of the present invention is to propose a left atrialappendage (LAA) closure immune from the insufficient strength problem asseen in the conventional devices.

To this end, the proposed LAA closure includes a plurality of supportingstruts distributed peripherally around a first hub and extendingoutwardly from the first hub, the supporting strut bifurcating at afirst position into a left branch and a right branch, the left branch ofa supporting strut and the right branch of an adjacent supporting strutjoining each other at a second position and extending distally to four adistal end, the LAA closure further including a supporting rod disposedbetween adjacent supporting struts.

Optionally, in the LAA closure, the supporting rod may have a first endconnected to the outside of the first hub, extending outwardly andbifurcating into a second end and a third end at a third position.

Optionally, in the LAA closure, the second end may be fixed between thefirst and second positions of the left branch of the supporting struts,and the third end may be fixed between the first and second positions ofthe right branch of the supporting struts.

Optionally, in the LAA closure, the second and third ends may be fixedon two adjacent supporting struts.

Optionally, in the LAA closure, a length of the supporting rod from thefirst hub to the third position may be smaller than a length of thesupporting strut from the first hub to the first position.

Optionally, in the LAA closure, the first, second and third ends of thesupporting rod may resume a Y shape.

Optionally, in the LAA closure, some or all of the supporting struts mayinclude a barb, and/or some or all of the left and right branches mayinclude a barb.

Optionally, in the LAA closure, the left and right branches of the samesupporting strut may be connected to each other at the distal endsthereof.

Optionally, in the LAA closure, each of the distal ends may be benttoward the proximal end to form an anchor.

Optionally, in the LAA closure, a length from the point where the distalend starts bending to a final point of the distal end may be greaterthan a length from a junction of the distal ends to the final point.

Optionally, in the LAA closure, the distal ends may extend inwardly toform a second hub.

Optionally, in the LAA closure, the distal ends may protrude radially toform an anchor.

Optionally, in the LAA closure, the first hub may be coaxial with thesecond hub.

Optionally, in the LAA closure, the first and second hubs may axiallyprotrude in the same direction or in opposite directions.

Optionally, at least a portion of the LAA closure may be covered with abiocompatible membrane.

Optionally, in the LAA closure, an angle formed between adjacentsupporting struts may be 45°.

In the proposed LAA closure, the plurality of supporting struts aredistributed peripherally around a first hub and extend outwardly fromthe first hub. Each supporting strut bifurcates at a first position intoleft and right branches. The left branch of a supporting strut is joinedwith the right branch of an adjacent supporting strut at the secondposition. The branches further extend distally to form distal endsthereof. Adjacent supporting struts are intervened by supporting rodswhich ensure stability, i.e., absence of irregular deformation andlateral slippage, of the LAA closure. In particular, the supportingstruts and the supporting rods between them together constitute a densemesh which imparts high overall strength to the LAA closure. Inaddition, in the proposed LAA closure, the anchors are integrally formedwith the self-expanding frame without requiring a separate fabricationprocess. The anchors can not only provide a strong anchoring effect, butcan also effectively prevent dislocation of the closure due to AF.Further, as the anchors' size is not excessive, they will not damage anytissue.

It is another objective of the present invention to propose a system fordelivering and deploying an LAA closure, which is capable of betterloading and deployment of the LAA closure.

To this end, the proposed delivery system includes a first deliverymember and a second delivery member inside the first delivery member.

The first delivery member is adapted to be engaged with or disengagedfrom a first hub of the LAA closure.

The second delivery member is adapted to be engaged with or disengagedfrom a second hub of the LAA closure.

Optionally, in the LAA closure delivery system, the first hub may beengaged with the second hub before the LAA closure is released from thesystem.

Optionally, the LAA closure delivery system may further include a sheathin which the first delivery member is received.

Optionally, the LAA closure delivery system may further include astopper for fixing the first delivery member relative to the seconddelivery member.

Optionally, in the LAA closure delivery system, the stopper may includea clamping portion and an actuation portion, the clamping portion isconfigured to partially or wholly pass through slots in the firstdelivery member to clamp the second delivery member.

Optionally, the LAA closure delivery system may further include a handleprovided at a proximal end of the first delivery member and/or at aproximal end of the second delivery member. The handle may be providedwith a visible mark.

Optionally, in the LAA closure delivery system, the LAA closure mayinclude a first portion and a second portion, the first portion has afirst end connected to the first hub and a second end connected to afirst end of the second portion, the second portion has a second endconnected to the second hub.

Optionally, in the LAA closure delivery system, the second portion maybe located inside the first portion before the LAA closure is releasedfrom the system.

Optionally, in the LAA closure delivery system, the first portion and/orthe second portion may be provided with a plurality of anchors.

Optionally, in the LAA closure delivery system, the first hub may definea step at a distal end thereof on which a proximal end of the second hubis located when the first hub is engaged with the second hub.

Optionally, in the LAA closure delivery system, the first hub mayinclude a groove at a proximal end thereof and the groove is configuredto receive a distal end of the first delivery member.

Optionally, in the LAA closure delivery system, the first deliverymember may be flared out at the distal end thereof.

Optionally, in the LAA closure delivery system, the first hub may beengaged with the second hub by an internal/external spline connection ora snap connection, in case of the first hub to be engaged with thesecond hub.

Optionally, in the LAA closure delivery system, the first deliverymember may be engaged with the first hub by a threaded connection, aninternal/external spline connection or a snap connection, and/or whereinthe second delivery member is engaged with the second hub by a threadedconnection, an internal/external spline connection or a snap connection.

In the proposed system for delivering and deploying an LAA closure,before the LAA closure is loaded, the first delivery member is coupledto the first hub of the LAA closure and the second delivery memberinside the first delivery member is coupled to the second hub thereof sothat the LAA closure can be crimped to allow the loading. This can avoidan excessive length of the LAA closure when it is loaded. In thedeployment process, the second portion of the LAA closure with anchorsis first released. At this point, repeated relocations are allowed untila suitable deployment site is reached. After that, the first and secondhubs of the LAA closure are released. Therefore, the proposed systemmakes it possible for the LAA closure to be better loaded or deployed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective structural schematic view of a left atrialappendage (LAA) closure according to a first embodiment of the presentinvention.

FIG. 2 is a top schematic view of the LAA closure according to the firstembodiment of the present invention.

FIG. 3 is a partially enlarged schematic view of the LAA closureaccording to the first embodiment of the present invention.

FIG. 4 is another partially enlarged schematic view of the LAA closureaccording to the first embodiment of the present invention.

FIG. 5 is a diagrammatical view of the LAA closure according to thefirst embodiment of the present invention deployed within the LAA.

FIG. 6 is a perspective structural schematic view of an LAA closureaccording to a second embodiment of the present invention.

FIG. 7 is a cutaway schematic view of the LAA closure according to thesecond embodiment of the present invention.

FIG. 8 is a cutaway schematic view of the LAA closure according to thesecond embodiment of the present invention in another configuration.

FIG. 9 is a cutaway schematic view of the LAA closure according to thesecond embodiment of the present invention in still anotherconfiguration.

FIG. 10 is a perspective structural schematic view of an LAA closureaccording to a third embodiment of the present invention.

FIG. 11 is a cutaway schematic view of an LAA closure according to afourth embodiment of the present invention.

FIG. 12 is a structural schematic of an LAA closure suited to bedelivered by a delivery system according to a fifth embodiment of thepresent invention.

FIG. 13 is a structural schematic of a system for delivering the LAAclosure according to the fifth embodiment of the present invention.

FIG. 14 schematically illustrates the system according to the fifthembodiment of the present invention prior to the deployment of the LAAclosure.

FIG. 15 schematically illustrates the system according to the fifthembodiment of the present invention, with the LAA closure beingpartially released.

FIG. 16 schematically illustrates the system according to the fifthembodiment of the present invention in another configuration, with theLAA closure being partially released.

FIG. 17 schematically illustrates the system according to the fifthembodiment of the present invention subsequent to complete deployment ofthe LAA closure.

FIG. 18 schematically illustrates the system according to the fifthembodiment of the present invention, with the LAA closure being anchoredwithin the LAA.

FIG. 19 is a structural schematic of a stopper according to the fifthembodiment of the present invention.

FIG. 20 schematically illustrates how the stopper according to the fifthembodiment of the present invention fixes a first delivery memberrelative to a second delivery member.

FIG. 21 schematically illustrates a system for delivering the LAAclosure according to a sixth embodiment of the present invention, withthe LAA closure being partially released.

FIG. 22 also schematically illustrates the system according to the sixthembodiment of the present invention, with the LAA closure beingpartially released.

FIG. 23 schematically illustrates the system according to the sixthembodiment of the present invention subsequent to complete deployment ofthe LAA closure.

FIG. 24 schematically illustrates a system for delivering the LAAclosure according to a seventh embodiment of the present invention, withthe LAA closure being partially released.

FIG. 25 schematically illustrates a system for delivering the LAAclosure according to an eighth embodiment of the present inventionsubsequent to complete deployment of the LAA closure.

FIG. 26 schematically illustrates the system according to the eighthembodiment of the present invention in another configuration subsequentto complete deployment of the LAA closure.

FIG. 27 schematically illustrates the system according to the eighthembodiment of the present invention in still another configurationsubsequent to complete deployment of the LAA closure.

FIG. 28 shows external splines according to the eighth embodiment of thepresent invention.

FIG. 29 shows internal splines according to the eighth embodiment of thepresent invention.

FIG. 30 shows the external and internal splines according to the eighthembodiment of the present invention that are connected together.

DETAILED DESCRIPTION

Left atrial appendage (LAA) closures and systems for their deliveryproposed in this invention will be described below in further detailwith reference to the accompanying drawings and a few specificembodiments. Features and advantages of the invention will be moreapparent from the following detailed description, and from the appendedclaims. It is noted that the figures are provided in a very simplifiedform not necessarily presented to scale, with the only intention tofacilitate convenience and clarity in explaining some embodiments of thepresent invention. In fact, these figures generally give emphasis ondifferent details and are accordingly drawn to different scales.

As used herein, the term “about” applies to all numeric values, whetheror not explicitly indicated. In the context of a numerical value, thisterm generally refers to a range of numbers that one of skill in the artwould consider equivalent to the recited value (i.e., having the samefunction or result). In many instances, the term may include numbersthat are rounded to the nearest significant figure. Unless otherwisespecified, the term “about” recited elsewhere herein (i.e., in thecontext other than numerical values) is assumed to have its ordinary andcustomary meaning as understood in the context of this specification andin consistency therewith.

As used herein, the terms “outward” or “outwardly” refer to a directionpointing away from an axis of the LAA closure, whether perpendicularlythereto or not, whilst the terms “inward” or “inwardly” refers to adirection pointing toward the axis, whether perpendicularly thereto ornot. The terms “proximal” and “distal” are used herein to describerelationships in terms of orientation, position and direction betweendifferent elements or actions from the perspective of a physician who isoperating the device. Yet without wishing to be limiting in any sense, a“proximal end” refers to an end nearer to the physician and a “distalend” to an end that first enters the body of the patient, when thedevice is operated normally.

As used herein and in the appended claims, the singular forms “a”, “an”,and “the” include plural references unless the context clearly dictatesotherwise. As used herein and in the appended claims, the term “or” isgenerally employed in its sense including “and/or” unless the contentclearly dictates otherwise.

Embodiment 1

Reference is now made to FIGS. 1 to 3, in which FIG. 1 illustrates aperspective structural schematic view of a left atrial appendage (LAA)closure according to a first embodiment of the present invention, FIG. 2illustrates a top schematic view of the LAA closure according to thefirst embodiment of the present invention, and FIG. 3 illustrates apartially enlarged schematic view of the LAA closure according to thefirst embodiment of the present invention. As shown in FIGS. 1 to 3, theLAA closure 1 includes a plurality of supporting struts 11. Thesupporting struts 11 are distributed around a first hub 10 and extendoutwardly from the first hub 10. Each supporting strut 11 bifurcates ata first position 110 into a left branch 111 and a right branch 112. Theleft branch 111 of each supporting strut 11 is joined with the rightbranch 112 of an adjacent one of the supporting struts 11 at a secondposition 113. The branches further extend distally to form distal endsthereof. The LAA closure 1 further includes supporting rods 12 eachinterposed between corresponding adjacent two of the supporting struts11. This design ensures stability, i.e., absence of irregulardeformation and lateral slippage, of the LAA closure 1. In particular,with the supporting rods 12 between the supporting struts 11, the LAAclosure 1 appears as a dense mesh which can further improve the overallstrength of the LAA closure 1.

Preferably, each supporting strut 11 is oriented at an angle of 45° withrespect to a neighboring supporting strut. That is, preferably, eightsupporting struts 11 are distributed around the first hub 10. Such anangular distribution of the supporting struts 11 imparts good stabilityand low deformability of the LAA closure 1 while allowing it to beeasily deployed or retrieved.

Specifically, with continued reference to FIGS. 1 to 3, each supportingrod 12 has a first end 120 connected to an outer side of the first hub10. Each supporting rod 12 extends outwardly from the first end 120 andbifurcates at a third position 121 into branches terminatingrespectively at a second end 122 and a third end 123. The second end 122is fixed on the left branch 111 at a location between the first andsecond positions 110, 113, and the third end 123 is fixed on the rightbranch 112 at a location between the first and second positions 110,113. Each pair of second end 122 and third end 123 are fixed on adjacenttwo of the supporting struts 11.

In other words, in this embodiment, each supporting rod 12 provides acertain support to corresponding adjacent two of the supporting struts11, resulting in a further increase in the stability of the LAA closure1 and, in particular, facilitating the avoidance of its irregulardeformation and lateral slippage.

Additionally, the section of each supporting rod 12 between the firsthub 10 and the third position 121 is shorter than the section of eachsupporting strut 11 between the first hub 10 and the first position 110.This can make the supporting rod 12 more stable, enabling a bettersupport for the corresponding supporting struts 11.

Preferably, the supporting rod 12 terminating at the three ends, i.e.,the first end 120, the second end 122 and the third end 123, resumes a Yshape. That is to say, the first end 120, the second end 122 and thethird end 123 of the supporting rod 12 constitute a symmetricalstructure. The Y shape is excellent in stability and reliability, sothat the supporting rod 12 is excellent in stability and reliability.Further, the third position 121 is located on the supporting rod 12 at alocation between one fifth to four fifth of a radial length of thesupporting rod 12. This is favorable to the formation of the supportingrod 12 by cutting a tube as well as to its subsequent expansion to astable final shape.

With continued reference to FIGS. 1 to 3, in this embodiment, some orall of the supporting struts 11 each have a barb 13, and/or some or allof the left and right branches 111, 112 each have a barb 13. These barbs13 can facilitate the attachment of the closure 1 to the LAA.Preferably, the barbs 13 are cut from the same single piece as thesupporting struts 11, the left branches 111 and/or the right branches112. This enables a simple fabrication process and high structuralreliability.

As shown in FIG. 1, in this embodiment, the left branch 111 and theright branch 112 of the same supporting strut 11 are connected to eachother at their distal ends. This can enhance the circumferentialstability of the supporting strut 11 and hence the stability andreliability of the LAA closure 1.

Reference is now made to FIG. 4, a partially enlarged schematic view ofthe LAA closure according to the first embodiment of the presentinvention. In this embodiment, the left branch 111 and the right branch112 of the same supporting strut 11, after being connected at the distalends, further extend to final points of the left branch 111 and theright branch 112. The sections of the left branch 111 and the rightbranch 112 extending from the final points to the distal ends are curvedover back to point proximally and hence each define an anchor 14. Theanchor 14 enables firm attachment of the LAA closure 1 to the LAA.

Preferably, with continued reference to FIG. 4, for each of the leftbranch and the right branch, the section between a bending point 115 andthe final point 116 is longer than the section between the distal endjunction 114 and the final point 116. Thus, the anchor 14 has a largedegree of curvature and is reinforced with the distal end junction 114.As a result, the anchor 14 is more structurally stable and can morefirmly hook onto the LAA, improving the attachment of the LAA closure 1to the LAA. Preferably, the section between the distal end junction 114and the final point 116 has a length ranging from 1 mm to 3 mm, and thesection extending from the bending point 115 to the distal end junction114 has a length that is smaller than 3 mm.

According to this embodiment, as the anchor is defined downstream of thedistal ends of the left and right branches 111, 112, i.e., terminatingat the distal end junction 114, an excessive length that may cause theanchor to pierce the heart tissue, or any damage to the LAA incurred bythe anchor, can be prevented.

According to this embodiment, the LAA closure 1 may be formed in oneintegral piece. In particular, its components including the first hub10, the supporting struts 11, the supporting rods 12 and the anchors 14may be formed by cutting a single tube. The integration enables a simplefabrication process and savings in manpower, materials and othereconomic costs.

Further, the LAA closure 1 may be at least partially covered with abiocompatible membrane.

Described below is how the LAA closure 1 can be used.

The LAA closure is advanced by a pusher through a route created with acatheter to a distal end of the catheter and to be deployed from thedistal end. During the deployment, the LAA closure 1 is released from asheath, so as to position and attach the anchors to the wall of the LAA.After that, the supporting struts 11 and the supporting rods 12 arecaused to expand to sufficiently abut and adhere to the LAA wall,thereby best occluding the LAA. In order to retrieve the closure,reverse operations may be performed to cause natural detachment of theanchors from the LAA wall.

Specifically, reference can be made to FIG. 5, which illustrates adiagrammatical view of the LAA closure according to the first embodimentof the present invention deployed within the LAA. After the LAA closure1 is deployed into the LAA 7, the LAA closure 1 is in an expandedconfiguration with the barbs 13 and the anchors 14 attached to the LAA7.

Embodiment 2

Reference is now made to FIGS. 6 and 7, in which FIG. 6 illustrates aperspective structural schematic view of an LAA closure according to asecond embodiment of the present invention and FIG. 7 illustrates acutaway schematic view of the LAA closure according to the secondembodiment of the present invention. As shown in FIGS. 6 and 7, the LAAclosure 3 includes a plurality of supporting struts 31. The supportingstruts 31 are distributed around a first hub 30 and extend outwardlyfrom the first hub 30. Each supporting strut 31 bifurcates at a firstposition 310 into a left branch 311 and a right branch 312. The leftbranch 311 of each supporting strut 31 is joined with the right branch312 of an adjacent one of the supporting struts 31 at a second position313. The branches further extend distally to form distal ends thereof.The LAA closure 3 further includes supporting rods 32 each interposedbetween corresponding adjacent two of the supporting struts 31.

Additionally, each supporting rod 32 has a first end 320 connected to anouter side of the first hub 30. Each supporting rod 32 extends outwardlyfrom the first end 320 and bifurcates at a third position 321 intobranches terminating respectively at a second end 322 and a third end323. The second end 322 is fixed on the left branch 311 at a locationbetween the first and second positions 310, 313, and the third end 323is fixed on the right branch 312 at a location between the first andsecond positions 310, 313. Each pair of the second end 322 and third end323 are fixed on adjacent two of the supporting struts 31.

Some or all of the supporting struts 31 each have a barb 33, and/or someor all of the left and right branches 311, 312 each have a barb 33. Theleft branch 311 and the right branch 312 of the same supporting strut 31are connected to each other at their distal ends. The distal ends of theleft branch 311 and the right branch 312 bent over back to pointproximally and hence define an anchor 34.

The structure described above is identical to that of the firstembodiment, and a detailed description is therefore deemed unnecessary.

The second embodiment differs from the first embodiment in that the LAAclosure 3 further includes a second hub 35. Specifically, the distalends extend inwardly to form a second hub 35. With continued referenceto FIG. 6, in particular, distal ends of all the left and right branches311, 312 extend inwardly to form the second hub 35. Additionally, thefirst hub 30 may be coaxial with the second hub 35. This imparts goodsymmetry to the LAA closure 3, which is favorable to its deployment andretrieval.

Described below is how the LAA closure 3 can be used.

The LAA closure is advanced by a pusher through a route created with acatheter to a distal end of the catheter and then released from a sheathin which it is loaded. During the deployment, the LAA closure 3 isreleased from the sheath, the anchors attach to the wall of the LAAfirst and the supporting struts 31 and the supporting rods 32 thenexpand to sufficiently abut and adhere to the LAA wall, thereby bestoccluding the LAA. In order to retrieve the device, reverse operationsmay be performed to cause natural detachment of the anchors from the LAAwall. According to this embodiment, with the inward extensionsproximally projecting from the distal ends and terminating at the secondhub 35, the LAA closure 3 can be better deployed and retrieved.

In the second embodiment, the distal ends are described to extendproximally to form the second hub 35. In other embodiments, the distalends may also extend distally to form the second hub 35, as shown inFIG. 8. In both of the foregoing cases, the first hub 30 and the secondhub 35 are illustrated as protruding in the same direction. While inother embodiments of the present invention, the first hub 30 and thesecond hub 35 may also protrude in opposite directions, as shown in FIG.9.

Embodiment 3

FIG. 10 is a perspective structural schematic view of an LAA closureaccording to a third embodiment of the present invention. As shown inFIG. 10, the LAA closure 4 includes a plurality of supporting struts 41.The supporting struts 41 are distributed around a first hub 40 andextend outwardly from the first hub 40. Each supporting strut 41bifurcates at a first position 410 into a left branch 411 and a rightbranch 412. The left branch 411 of each supporting strut 41 is joinedwith the right branch 412 of an adjacent one of the supporting struts 41at a second position 413. The branches further extend distally to formdistal ends thereof. The LAA closure 4 further includes supporting rods42 each interposed between corresponding adjacent two of the supportingstruts 41. Extensions projecting inwardly from the distal ends terminateat a second hub 45.

In addition, each supporting rod 42 has a first end 420 connected to anouter side of the first hub 40. Each supporting rod 42 extends outwardlyfrom the first end 420 and bifurcates at a third position 421 intobranches terminating respectively at a second end 422 and a third end423. The second end 422 is fixed on the left branch 411 at a locationbetween the first and second positions 410, 413, and the third end 423is fixed on the right branch 412 at a location between the first andsecond positions 410, 413. Each pair of the second end 422 and third end423 are fixed on adjacent two of the supporting struts 41.

Some or all of the supporting struts 41 each have a barb 43, and/or someor all of the left and right branches 411, 412 each have a barb 43.

The third embodiment differs from the second embodiment in that the leftbranch 411 and the right branch 412 of the same supporting strut 41 arecurved at their distal ends to define anchors 44 without joining witheach other at their distal ends. Such anchors 44 according to thisembodiment also allow firm attachment of the LAA closure 4 to the LAA.

Embodiment 4

FIG. 11 is a cutaway schematic view of an LAA closure according to afourth embodiment of the present invention. The fourth embodiment isessentially identical in structure to the first embodiment except thatthe supporting struts and supporting rods in this embodiment aredouble-layered nickel titanium (nitinol) components, which impart higherquality and stability to the LAA closure 5.

In each of the LAA closures according to the second and thirdembodiments, the first and second hubs and the components connectingthem together (i.e., the supporting struts and the supporting rods,which form a dense mesh) together form a structure resembling a closedcage. Hereinafter, such devices are thus referred to closed cage-likeLAA closures.

With such a closed cage-like LAA closure as shown in FIG. 12 as anexample, a detailed description will be given below about how systemsfor delivering the LAA closure are structured and work. The LAA closureof FIG. 12 may be the same as or similar to that of FIG. 6 according tothe second embodiment, and a perspective structural schematic view of itis shown in FIG. 12 in which, for the sake of simplicity, only the firsthub 30, the anchors 34, the second hub 35 and the cage-like structure 36are indicated. As shown in FIG. 12, the LAA closure 3 includes the firsthub 30, the second hub 35 and the cage-like structure 36 that connectsthe first hub 30 and the second huh 35 together. The anchors 34 areformed on the cage-like structure 36. Preferably, the anchors 34 may bedistributed on the cage-like structure 36 in multiple rows, thusenabling easier attachment of the LAA closure 3 to the LAA with higherstability and reliability.

It is noted that the closed cage-like LAA closure may also assume one ofconfigurations other than as shown, which are also suitable for thedelivery by the system. In addition, apart from the most typicalcage-like structure, the LAA closure may also be otherwise constructedwithout departing from the scope of the present invention.

Embodiment 5

FIG. 13 is a structural schematic of a system for delivering the LAAclosure according to a fifth embodiment of the present invention. Asshown FIG. 13, the system 6 includes a first delivery member 60 and asecond delivery member 61 inside the first delivery member 60. The firstdelivery member 60 may be coupled to or separated from the first hub 30(of the LAA closure 3), and the second delivery member 61 may be coupledto or separated from the second hub 35 (of the LAA closure 3).Specifically, in order to load the LAA closure 3, the first deliverymember 60 is coupled to the first hub 30 of the LAA closure 3 and thesecond delivery member 61 is coupled to the second hub 35 of the LAAclosure 3 so that the LAA closure 3 can be crimped to allow the loading.This design can avoid an excessive length of the LAA closure 3 when itis loaded.

Reference is now made to FIG. 14, a schematic illustration of the systemaccording to this embodiment before the LAA closure is deployed. Asshown in FIG. 14, in this embodiment, the system 6 further include asheath 62. The first delivery member 60 is loaded inside the sheath 62.Additionally, before the LAA closure 3 is deployed from the system 6,the first delivery member 60 is coupled to the first hub 30 and thesecond delivery member 61 is coupled to the second hub 35. Further, thefirst hub 30 may be engaged with the second hub 35 so that the LAAclosure 3 is crimped and has a length much smaller than that when it isloaded in the sheath 62 with the first hub 30 and the second hub 35being separate from each other. This is even more favorable to thedeployment of the LAA closure 3.

In the crimped configuration of the LAA closure 3 shown in FIG. 14, thecage-like structure 34 has a first portion 360 and a second portion 361.The first portion 360 is connected to the first hub 30 at one end and tothe second portion 361 at the other end, and the other end of the secondportion 361 is connected to the second hub 35. In this embodiment,several anchors 34 may be formed on each of the first portion and secondportions 360, 361 of the LAA closure 3. Before the LAA closure 3 isdeployed from the system 6, the second portion 361 is located internalto the first portion 360. The first portion 360 vertically overlaps thesecond portion 361, resulting in a significant reduction in the lengthof the LAA closure 3 when it is loaded in the sheath. Since the LAAclosure 3 is crimped when loaded within the system 6, with the anchors34 on the second portion 361 hidden in the interior space, they will notcome into contact or scratch the sheath 62 during entry into or movementwithin the sheath 62.

Reference is made further to FIGS. 15 to 17, which show how the LAAclosure 3 is deployed.

At first, as shown in FIG. 15, the first delivery member 60 and thesecond delivery member 61 are pushed from the sheath 62 so that the LAAclosure 3 (see FIGS. 6 and 12) gradually emerges from the sheath 62.Specifically, the first portion 360 of the LAA closure 3 and the anchors34 thereon first come out of the sheath 62. At this point, the system 6remains in connection with the LAA closure 3, i.e., the LAA closure 3 isstill under control of the system 6, allowing the physician to relocatethe device through changing positions of attachment of the anchors 34 tothe LAA.

Subsequently, as shown in FIG. 16, the second delivery member 61 ispushed out of the sheath 62 (with the first delivery member 60 eithernot being pushed any longer or pushed to advance slower) until theremaining part of the LAA closure 3 leaves the sheath 62. Again, at thispoint, as the first and second hubs 30, 35 remain in connection with thefirst and second delivery members 360, 361, i.e., the LAA closure 3remains controllable (by the physician), the physician is still capableof relocating the device through changing positions of attachment of theanchors 34 to the LAA.

Next, as shown in FIG. 17, after the LAA closure 3 has been deployed inplace within the LAA, the physician may completely deploy the LAAclosure 3. The deployment may in particular include: separating thesecond delivery member 61 from the second hub 35 b; and separating thefirst delivery member 60 from the first hub 30. At this point, the LAAclosure 3 cannot be relocated any longer.

With continued reference to FIG. 17, in this embodiment, the seconddelivery member 61 may be engaged with the second hub 35 by a threadedconnection. Tightening or loosening the threaded connection can lead tothe engagement or disengagement between the second delivery member 61and the second hub 35. In other embodiments, the second delivery member61 may also be otherwise engaged with the second hub 35, for example bya spline connection or a snap connection.

In this embodiment, the engagement between the first hub 30 and thesecond hub 35 may be accomplished by the following approach: a distalend of the first hub 30 includes a step 300, when the first hub 30 isengaged with the second hub 35, a proximal end of the second hub 35 iswithin the step 300. The first delivery member 60 may be coupled to thefirst hub 30 by inserting a distal end of the first delivery member 60into a groove 301 defined at a proximal end of the first hub 30. Thisconnection between the first delivery member 60 and the first hub 30 canbe easily established and the disconnection between the first deliverymember 60 and the first hub 30 can also be easily established during thedeployment process.

With the above steps completed, the LAA closure 3 will attach to andhence occlude the LAA 7 (see FIGS. 18 and 6).

With additional reference to FIGS. 19 and 20, in which FIG. 19illustrates a stopper according to the fifth embodiment of the presentinvention; FIG. 20 schematically illustrates how the stopper accordingto the fifth embodiment of the present invention fixes a first deliverymember relative to a second delivery member. In the embodiment of thepresent invention, the system 6 may further include a stopper 63 forfixing the second delivery member 61 relative to the first deliverymember 60. Specifically, the stopper 63 includes a clamping portion 630and an actuation portion 631. The clamping portion 630 includesprotrusions that can pass through slots 64 in the first delivery member60 and clamp the second delivery member 61. The stopper 63 allows easilycontrol the first delivery member 60 and the second delivery member 61,and hence achieve the simultaneous advancement and other operations onthe first delivery member 60 and the second delivery member 61. Theactuation portion 631 is provided with a spring 632 for immobilizationof the clamping portion 630.

Referring back to FIG. 13, the system 6 may further includes a handle65. In the embodiment of the present invention, the handle 65 isproposed at a proximal end of the first delivery member 60. The clampingand advancement of the handle 65 also allow easy advancement of thefirst and second delivery members 60, 61 within the sheath 62 andeventual deployment of the LAA closure 3. Preferably, the handle 65 isprovided with a visible mark indicating rotation directions in which thethreaded connection between the second delivery member 61 and the secondhub 35 can be tightened or loosened to cause the engagement ordisengagement between the second delivery member 61 and the second hub35.

In this embodiment, the LAA closure 3 can be deployed as describedbelow.

The handle 65 or the stopper 63 is manipulated to cause the firstdelivery member 60 and the second delivery member 61 to advance withinthe sheath 62 so that a first portion of the LAA closure 3 is deployed(under the distal push of the first delivery member 60 and the seconddelivery member 61). At this point, repeated relocations and adjustmentsare possible. After the first portion is deployed in place, the stopper63 is deployed and the threaded connection between the second deliverymember 61 and the second hub 35 is loosened so that the LAA closure 3covers the LAA 7. The first delivery member 60 is then retracted tocompletely deploy the LAA closure 3.

In summary, the system for delivering the LAA closure according to thisembodiment can avoid an excessive length of the LAA closure when it isloaded in the sheath. Meanwhile, since repeated relocations during thedeployment are possible, the LAA closure can be better loaded into anddeployed from the sheath.

Embodiment 6

FIGS. 21 to 23 show a system for delivering the LAA closure according toa sixth embodiment of the present invention, with the LAA closure beingpartially released. As shown in these figures, the system 8 includes afirst delivery member 80 and a second delivery member 81 inside thefirst delivery member 80. The first delivery member 80 may be coupled toor separated from the first hub 30 (of the LAA closure 3), and thesecond delivery member 81 may be coupled to or separated from the secondhub 35 (of the LAA closure 3). Specifically, in order to load the LAAclosure 3, the first delivery member 80 is coupled to the first hub 30of the LAA closure 3 and the second delivery member 81 is coupled to thesecond hub 35 of the LAA closure 3 so that the LAA closure 3 can becrimped to allow the loading. This design can avoid an excessive lengthof the LAA closure 3 when it is loaded.

In this embodiment, the second delivery member 81 is engaged with thesecond hub 35 in the same manner as the first embodiment, i.e., by athreaded connection.

Differing from the first embodiment, the first delivery member 80 isalso engaged with the first hub 31 by a threaded connection in thisembodiment.

Further, in this embodiment, each of the first delivery member 80 andthe second delivery member 81 is provided with a handle 83 at theproximal end. The handle 83 at the proximal end of the second deliverymember 81 enables independent advancement of the second delivery member81. Furthermore, each of the handles 83 of the first delivery member 80and the second delivery member 81 may be provided with a visible mark.In this embodiment, the mark on the handle 83 at the proximal end of thefirst delivery member 80 indicates rotation directions in which thethreaded connection between the first delivery member 80 can the firsthub 31 can be tightened or loosened. Similarly, the mark on the handle83 at the proximal end of the second delivery member 81 indicatesrotation directions in which the threaded connection between the seconddelivery member 81 and the second hub 35 can be tightened or loosened.In this way, the first delivery member 80 and the second delivery member81 can be easily connected to or separated from the first hub 31 and thesecond hub 35, respectively.

Moreover, the delivery system 8 may also include a sheath, a stopper andother components (including those not specified in this embodiment) thatare the same as the first embodiment. These components will not bedetailed again here, and reference can be made to the first embodimentfor their details.

With continued reference to FIGS. 21 to 23, in this embodiment, the LAAclosure 3 can be deployed as described below.

The handles 83 or the stopper (not shown) are/is manipulated to causethe first delivery member 80 and the second delivery member 81 toadvance within the sheath 82 so that a first portion of the LAA closure3 is deployed (under the distal push of the first delivery member 80 andthe second delivery member 81). At this point, repeated relocations andadjustments are possible. After the first portion is deployed in place,the stopper is released and the threaded connection between the seconddelivery member 81 and the second hub 35 is loosened so that the LAAclosure 3 covers the LAA 7. The threaded connection between the firstdelivery member 80 and the first hub 35 is then released to completelydeploy the LAA closure 3.

In summary, the system for delivering the LAA closure according to thisembodiment can avoid an excessive length of the LAA closure when it isloaded in the sheath. Meanwhile, since repeated relocations during thedeployment are possible, the LAA closure can be better loaded into andreleased from the sheath.

Embodiment 7

FIG. 24 shows a system for delivering the LAA closure according to aseventh embodiment of the present invention, with the LAA closure beingpartially released. As shown in FIG. 24, the system 9 according to thisembodiment includes a first delivery member 90 and a second deliverymember 91 inside the first delivery member 90. The first delivery member90 may be coupled to or separated from the first hub 30 (of the LAAclosure 3), and the second delivery member 91 may be coupled to orseparated from the second hub 35 (of the LAA closure 3). Specifically,in order to load the LAA closure 3, the first delivery member 90 iscoupled to the first hub 30 of the LAA closure 3 and the second deliverymember 91 is coupled to the second hub 35 of the LAA closure 3 so thatthe LAA closure 3 can be crimped to allow the loading. This design canavoid an excessive length of the LAA closure 3 when it is loaded.

In this embodiment, the first delivery member 90 is flared at the distalend and the second delivery member 91 can be engaged with the second hub35 by a threaded connection. The first delivery member 90 is fixed tothe first hub 30 by abutting the first delivery member 90 to the firsthuh 30. Due to the flared portion of the first delivery member 90, whenthe second delivery member 91 is engaged with the second hub 35 by athreaded connection, the first delivery member 90 is abutted to thesecond hub 35, enabling the LAA closure 3 to be crimped.

Again, the delivery system 9 may also include a sheath, a stopper, ahandle and other components (including those not specified in thisembodiment) that are the same as the first embodiment. These componentswill not be detailed again here, and reference can be made to the firstembodiment for their details.

The LAA closure 3 can be deployed as described below.

The first delivery member 90 and the second delivery member 91 areadvanced within the sheath 92 so that a first portion of the LAA closure3 is released (under the distal push of the first delivery member 90 andthe second delivery member 91). At this point, repeated relocations andadjustments are possible. After the first portion is deployed in place,the threaded connection between the second delivery member 91 and thesecond huh 35 is loosened so that the LAA closure 3 covers the LAA 7.The first delivery member 90 is then retracted to completely deploy theLAA closure 3.

In summary, the system for delivering the LAA closure according to thisembodiment can avoid an excessive length of the LAA closure when it isloaded in the sheath. Meanwhile, since repeated relocations during thedeployment are possible, the LAA closure can be better loaded into anddeployed from the sheath.

Embodiment 8

A system for delivering the LAA closure according to an eighthembodiment includes a first delivery member and a second delivery memberinside the first delivery member. The first delivery member may becoupled to or separated from the first hub 30 (of the LAA closure 3),and the second delivery member may be coupled to or separated from thesecond hub 35 (of the LAA closure 3). Specifically, in order to load theLAA closure 3, the first delivery member 90 is coupled to the first hub30 of the LAA closure 3 and the second delivery member 91 is coupled tothe second hub 35 of the LAA closure 3 so that the LAA closure 3 can becrimped to allow the loading. This design can avoid an excessive lengthof the LAA closure 3 when it is loaded.

This embodiment differs from the fifth, sixth or seventh embodimentessentially in that the first hub can be engaged with the second hub.

Specifically, reference can be made to FIGS. 25 and 26, in which FIG. 25illustrates a schematic illustration of the system according to thisembodiment, with the LAA closure having been completely deployed, andFIG. 26 illustrates a schematic illustration of the system according tothis embodiment in another configuration, with the LAA closure havingbeen completely deployed. As shown in FIGS. 25 and 26, after the LAAclosure has been completely deployed, the first hub 30 may be partiallyor wholly engaged with the second hub 35. The partial or wholeengagement of the first hub 30 and the second hub 35, coupled with theposition of engagement, allows the LAA closure to be better adapted tothe particular anatomical geometry of the LAA. Specifically, when theLAA is small in size, engagement of the second hub 35 with an upperportion of the first hub 30 (see FIG. 25) will result in a betteradaptation of the LAA closure to the LAA. When the LAA is rather bulky,the LAA closure will be better adapted to the LAA when the second hub 35is engaged with a lower portion of the first hub 30 (see FIG. 26). Whenthe LAA is even bigger, the second hub 35 is desired to be disengagedfrom the first hub 30 (see FIG. 27) so that the LAA closure can bebetter adapted to the LAA.

The first hub 30 may be engaged with the second hub 35 by a snapconnection or by an internal/external spline connection. For example,the first hub 30 may be engaged with the second hub 35 by a snapconnection (see FIGS. 25 to 27) including internal snapping lips on thefirst hub 30 and external snapping lips on the second hub 35.Alternatively, the first hub 30 may be engaged with the second hub 35 byan internal/external spline connection (see FIGS. 28 to 30) includinginternal spines on the first hub 30 and external splines on the secondhub 35.

Further, the first hub 30 may have an external thread that can engage aninternal thread on the first delivery member. Further, the second hub 35may have an internal thread that can engage an external thread on thesecond delivery member.

As stated above, in each of the foregoing LAA closure delivery systems,before the LAA closure is loaded, the first delivery member is coupledto a first hub of the LAA closure and the second delivery member insidethe first delivery member is coupled to a second hub thereof so that theLAA closure can be crimped to allow the loading. This design can avoidan excessive length of the LAA closure when it is loaded. In thedeployment process, a second portion of the LAA closure with anchors isfirst released. At this point, repeated relocations are allowed until asuitable deployment site is reached. After that, the first and secondhubs of the LAA closure are deployed. Therefore, the proposed systemsmake it possible for the LAA closure to be better loaded or deployed.

The description presented above is merely that of a few preferredembodiments of the present invention and does not limit the scopethereof in any sense. Any and all changes and modifications made bythose of ordinary skill in the art based on the above teachings fallwithin the scope as defined in the appended claims.

1. A left atrial appendage (LAA) closure delivery system used fordeploying the LAA, the delivery system comprising a first deliverymember and a second delivery member inside the first delivery member,wherein the first delivery member is adapted to be engaged with ordisengaged from a first hub of the LAA closure, the second deliverymember is adapted to be engaged with or disengaged from a second hub ofthe LAA closure.
 2. The LAA closure delivery system according to claim1, wherein the first hub is engaged with the second hub before the LAAclosure is released from the system.
 3. The LAA closure delivery systemaccording to claim 1, further comprising a sheath in which the firstdelivery member is received.
 4. The LAA closure delivery systemaccording to claim 1, further comprising a stopper for fixing the firstdelivery member relative to the second delivery member.
 5. The LAAclosure delivery system according to claim 1, further comprising ahandle provided at a proximal end of the first delivery member and/or ata proximal end of the second delivery member, being provided with avisible mark.
 6. The LAA closure delivery system according to claim 1,wherein the LAA closure comprises a first portion and a second portion,the first portion having a first end connected to the first hub and asecond end connected to a first end of the second portion, the secondportion having a second end connected to the second hub.
 7. The LAAclosure delivery system according to claim 6, wherein the second portionis located inside the first portion before the LAA closure is releasedfrom the system.
 8. The LAA closure delivery system according to claim1, wherein the first delivery member is flared at a distal end of thefirst delivery member.
 9. The LAA closure delivery system according toclaim 1, wherein the second delivery member is engaged with the secondhub by a threaded connection.